Shot shell and process of making same



Patented Dec. 10, 1935 UNI-TED STATES PATENT. OFFICE aozassa sno'r SHELL AND PROCESS or MAKING SAME ware

No Drawing. Application August 19,1930, Serial In Canada March 6, 1930 2 Claims. (01. 91 68) This invention relates to shot shells and processes of treating same and it comprises a shot gun shell having a paper body provided with a coating layer of cellulose ester composition in cohesive engagement and having the paper body impregnated interiorly with a waterproofing composition such as paraifin.

The main object of the invention is to provide shot shells which will be moisture proof and unaffected by atmospheric conditions; which can be fired in rapid succession without tending to stick in the hot gun barrel; which do not tend to stick in the breach; which are strong, durable and sufficiently rigid to withstand the rough usage to which shot shells are generally subjected in and out of the gun; and which are at the same time sufliciently elastic to allow for the necessary to rupture.

Shot shells are usually made of cardboard or heavy paper. It is recognized that absorption of moisture creates difliculties of various kinds and particularly swelling. Any substantial absorption of moisture and swelling may render it difiicult to handle a shell by the gun mechanism. Various methods of water proofing shells have been employed and various compositions have been used in rendering shells moisture proof. One method, that has been successfully employed, is to first impregnate the interior of the shells with a water proofing composition such as paramn and then after treating the surface of the parafiln shells, to coat same with a certain type of composition such as duco compositions in order to apply a coating that will remain in permanent cohesive engagement with the surface of the shell. Certain difliculties have been found in providing a composition that will bond or remain in cohesive engagement with a surface to which paramn has been applied in order to obtain consistent results, special conditions are required as it is a well recognized fact that pyroxylin or other celluloseester compositions, do not adhere satisfactorily under ordinary conditions, to a waxy or greasy surface owing to the tendency of the solvents. used in such compositions to dissolve the grease, bring it to the surface of the film and prevent proper drying.

One of the objects of my invention is to obviate the difiiculties heretofore encountered by first applying the cellulose ester coating to the surface of the paper container and then after the coating has set to impregnate the paper container interiorly with a paraflln composition. I have discovered that penetration of a waterproofing composition such as paraflln into a I paper shell or. container is accomplished largely through the ends of the cardboard container; rather than through the cylindrical surface of shell could not thus be penetrated. A short shell, however, say of about the length of the ordinary shot shell, will when dipped in a bath be- 15 come interiorly impregnated owing to the capillary action of the fibres on the waterproofing composition. The cellulose ester composition will bond much more readily with the surface of a paper container which has not been water- 20 proofed or paraflined and the absence of wax or grease at this stage of the process enables me to use compositions without consideration of their solvent properties for grease. Further, I am not-restricted to the use of pyroxylin or cellulose nitrate but may employ cellulose acetate or other cellulose ester.

My invention consists in reversing the steps of procedure and applying to the untreated surface so after the cellulose ester composition, the latter 40 will bond and remain in cohesive engagement with the fibres of the shell much more effectively than if applied to a surface which has been subjected to a bath of paraflin. The amount of paraffin which is used for impregnating the paper 45 container may be controlled. While I prefer to use cellulose ester compositions which. will bond cohesively with the fibres of the paper, much more latitude is permitted in 1 1 use of such compositions than if they were 50 applied to a surface which had previously been coated with wax. Generally, a composition containing a little drying oil and a certain amount of natural or synthetic resin is preferable.

I claim:

1. The steps of preparing a shotgun shell which consists in first coating paper shells with a cellulose' ester composition and then impregnating the wall of the paper container between .the inner and outer'surfaces with a vpara 11in com- 

